Change Details

Historically, BSD cp has followed symbolic links in the destination when copying recursively, while GNU cp has not. POSIX is somewhat vague on the topic, but both interpretations are within bounds. In 33ad990ce974, cp was changed to apply the same logic for symbolic links in the destination as for symbolic links in the source: follow if not recursing (which is moot, as this situation can only arise while recursing) or if the `-L` option was given. There is no support for this in POSIX. We can either switch back, or go all the way. Having carefully weighed the kind of trouble you can run into by following unexpected symlinks up against the kind of trouble you can run into by not following symlinks you expected to follow, we choose to go all the way. MFC after: never Relnotes: yes Sponsored by: Klara, Inc.

Historically, BSD cp has followed symbolic links in the destination when copying recursively, while GNU cp has not. POSIX is somewhat vague on the topic, but both interpretations are within bounds. In 33ad990ce974, cp was changed to apply the same logic for symbolic links in the destination as for symbolic links in the source: follow if not recursing (which is moot, as this situation can only arise while recursing) or if the `-L` option was given. There is no support for this in POSIX. We can either switch back, or go all the way. Having carefully weighed the kind of trouble you can run into by following unexpected symlinks up against the kind of trouble you can run into by not following symlinks you expected to follow, we choose to go all the way. Note that this means we need to stat the destination twice: once, following links, to check if it is or references the same file as the source, and a second time, not following links, to set the dne flag and determine the destination's type. While here, remove a needless complication in the dne logic. We don't need to explicitly reject overwriting a directory with a non-directory, because it will fail anyway. Finally, add test cases for copying a directory to a symlink and overwriting a directory with a non-directory. MFC after: never Relnotes: yes Sponsored by: Klara, Inc.

Historically, BSD cp has followed symbolic links in the destination when copying recursively, while GNU cp has not. POSIX is somewhat vague on the topic, but both interpretations are within bounds. In 33ad990ce974, cp was changed to apply the same logic for symbolic links in the destination as for symbolic links in the source: follow if not recursing (which is moot, as this situation can only arise while recursing) or if the `-L` option was given. There is no support for this in POSIX. We can either switch back, or go all the way. Having carefully weighed the kind of trouble you can run into by following unexpected symlinks up against the kind of trouble you can run into by not following symlinks you expected to follow, we choose to go all the way. Note that this means we need to stat the destination twice: once, following links, to check if it is or references the same file as the source, and a second time, not following links, to set the dne flag and determine the destination's type. While here, remove a needless complication in the dne logic. We don't need to explicitly reject overwriting a directory with a non-directory, because it will fail anyway. Finally, add test cases for copying a directory to a symlink and overwriting a directory with a non-directory. MFC after: never Relnotes: yes Sponsored by: Klara, Inc.